OPA861
www.ti.com
SBOS338–AUGUST 2005
TYPICAL CHARACTERISTICS: VS = ±5V
At TA = +25°C, IQ = 5.4mA, and RL = 500Ω, unless otherwise noted.
OTA TRANSCONDUCTANCE vs FREQUENCY
OTA TRANSCONDUCTANCE vs QUIESCENT CURRENT
1000
100
10
150
IO UT
VIN = 100mVPP
Ω
RL = 50
VIN
VIN = 10mVPP
Ω
50
120
90
Ω
50
IQ = 5.4mA (102mA/V)
IQ = 6.5mA (117mA/V)
IOUT
60
VIN
Ω
50
IQ = 1.9mA (51mA/V)
Ω
50
30
0
IQ = 3.4mA (79mA/V)
1M
10M
100M
Frequency (Hz)
1G
6
7
8
9
10
11
12
13
Quiescent Current (mA)
Figure 1.
Figure 2.
OTA TRANSCONDUCTANCE vs INPUT VOLTAGE
OTA TRANSFER CHARACTERISTICS
160
140
120
100
80
8
6
4
2
0
IQ = 6.5mA
IQ = 5.4mA
IQ = 6.5mA
IQ = 5.4mA
IQ = 3.4mA
IQ = 3.4mA
IQ = 1.9mA
IOUT
−
60
2
4
6
8
IQ = 1.9mA
VIN
−
−
−
40
Ω
50
Ω
50
20
Small signal around input voltage.
0
−
−
−
−
−
−
−
−
−
−
−
40
30
20
10
0
10
20
30
40
70 60 50 40 30 20 10
0
10 20 30 40 50 60 70
Input Voltage (mV)
OTA Input Voltage (mV)
Figure 3.
Figure 4.
OTA SMALL-SIGNAL PULSE RESPONSE
OTA LARGE-SIGNAL PULSE RESPONSE
0.8
0.6
0.4
0.2
0
3
2
1
0
−
−
−
−
0.2
0.4
0.6
0.8
G = +5V/V
−
G = +5V/V
1
2
3
Ω
RL = 500
Ω
RL = 500
VIN = 1VPP
fIN = 20MHz
See Figure 48
VIN = 0.25VPP
fIN = 20MHz
See Figure 48
−
−
Time (10ns/div)
Time (10ns/div)
Figure 5.
Figure 6.
7
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